Operating mechanism for salvo



1964 R. F. MAGARDO ETAL 3,

OPERATING MECHANISM FOR SALVO-TYPE GUNS s Sheets-Sheet 2 Filed Dec. 27, 1962 l2 El F'gLEL 5a 3 o 5 I06 42 36 42 l4 i ,f

r ny I Dal-111111 Ejluflmu-n M BY ,QJQZJM; a. a @MWZL Dec. 8, 1964 R. F. MAGARDO ETAL 3,160,063

OPERATING MECHANISM F OR SALVO-TYPE GUNS Filed Dec. 27, 1962 5 Sheets-Sheet 3 I )IIIIIIIIIIIIIIIL INVENTOR Ember]: EMnjurflu Ilunu'lrl [lEudm-nn BY ,gj 2 2501; P4 dQM OPERATING MECHANISM FOR SALVG= TYPE GUNS Robert F. Magardo, Springfield, and Donald C. Dadmun, Northampton, Mass., assignors to the United States of America as represented by the Secretary of the Army Filed Dec. 27, 1962, Ser. No. 247,772 9 Claims. (Cl. 89-127) (Granted under Title 35, U.S. Code (1952), sec. 266) This invention described herein may be manufactured and used by or for the Government for governmental purposes Without the payment to us of any royalty there- This invention relates to the operating mechanisms for guns and more particularly to the operating mechanisms for firearms of salvo-type in which a plurality of rounds are fired together in each salvo sequence.

Up to the present time, automatic salvo weapons'discharge the salvos by simultaneous release of spring-biased firing pins. Trouble has been encountered with such weapons because .of the variances in ammunition detonating components, whereby it is impossible to maintain the simultaneous ignition of all of the rounds which assures that the breech mechanism will not open before the pressure in all of the chambers is below the safe unlocking limit. Moreover, the simultaneous discharge of several rounds in a weapon of shoulder-type produces an extremely high recoil impact against the shooter.

It is, therefore, one object of this invention to provide for salvo weapons an operating mechanism which assures that all rounds are fired and that the chamber pressures are all below the safe limit before the breech mechanism is opened.

It is a further object of this invention to provide such an operatingmechanism which reduces the initial recoil energy by dividing the recoil energy into a series ofoneround impulses.

It is another object of this invention to provide such an operating mechanism whereby the discharge of the first round is effected by a scar controlled firing pin, the gases of the discharge are tapped to a second firing pin for discharge of the second round, these gases are then tapped to a third firing pin and so on until the last round is fired with the gases from the last round being utilized to actuate the bolt mechanism for opening the breech.

The specific nature of the invention as well as other objects and advantages thereof will clearly appear from a description of a preferred embodiment as shown in the accompanying drawings in which:

FIG. 1 is a longitudinally cross-sectioned view of the receiver and barrel of a salvo firearm;

FIG. 2 is a view taken along line 22 of FIG. 1; FIG. 3 is a view taken along line 3--3 of FIG. 2; FIG. 4 is a view taken along line 4-4 of FIG. 2; FIG. 5 is a view taken along line 55 of FIG. 2; FIG. 6 is a view taken along line 66 of FIG. 2; FIG. 7 is a view taken along line 7-7 of FIG. 6;

1 FIG. 8 is a View taken along line 3-8 of FIG. 1;

FIG. 9 is an exploded perspective View of the bolt assembly; and

FIG. 10 is a view taken along line lll1tl of FIG. 1.

Shown in the figures is a firearm 12 having a receiver 14- and a barrel 16 provided with three laterally spaced bores 18 each having a chamber 20 for receiving a cartridge 22 for discharge. A bolt assembly 24 is mounted for longitudinal reciprocation in receiver 14, as hereinafter described, so as to transfer three cartridges 22 simultaneously from a magazine 26 into chambers 20, support the bases of the cartridges for discharge, assist in discharge of the cartridges, and extract the fired cases. A recess ZS-extends rearwardly into receiver 14 from the 3,12%,3 Patented Dec. 8, 1964 front end to receive the rear end of barrel l6 and an opening 30 extends forwardly from the rear end of the receiver to form a chamber for bolt assembly 24. A

lateral partition 32 separates recess 28 and opening 30.

Bolt assembly 24 includes a rear member 34 and a front member 36, which are arranged for relative longitudinal displacement, and a cylindrical member 38 which is carried by the front member and is arranged for rotation therein as hereinafter described. The front end of front member 36 is bifurcated by a vertical slot 4b which forms a pair of laterally spaced breechblocks 42 and a wall 44- at the rear end of the slot. A bore 45 extends rearwardly through front member 36 from wall 44 for rotatingly mounting cylindrical member 38. A tang 48 on cylindrical member 38 is received by an annular channel 56 in the wall of the bore 46 to permit rotation of the cylindrical member without translation. Cylindrical member 38 includes an integral cylindrical head 52 on the front end thereof.

Tang 43 and channel 5% are arranged so that the front end of head 52 is positioned thereby even with the front ends of the breechblocks 4 2. Extending through partition 32 is a cylindrical aperture 56 which is arranged to receive head 52, when front member 36 is in battery position, so as to permit contact of the front endof the head with the breech end of barrel is to block the breech end of the center one of the bores 18. Mating holes 58 through partition 32 receive breechblocks 42, when front member 36 is in battery position, to permit contact of the breechblocks with the breech end of barrel is to block the breech ends of the two outside ones of the bores 18. Conventional extractors 59 are mounted on head 52 and breechblocks 42 for engagement with the extractor grooves of cartridges 22 to provide extraction of the fired cases therefrom during rearward displacement of front member 36. Cooperating bayonet-type lugs 69 are provided on head SZand in aperture 56 so that, when the head is fully received in the aperture and is rotated 90, the lugs engage to lock the head to partition The rear end of cylindrical member 33 is received by a mating bore 62 in rear member 34 and a transverse pin 64 therethrough extends through such bore and a cam slot 66 formed in the cylindrical member. Cam slot 66 is formed so that, when rear member 34 is displaced forwardly relative to front member 36, cylindrical member 38 is rotated 90 to a locked position wherein the cooperating lugs 65 are in engagement and so that, when the rear member is displaced rearwardly relative to the front member, the cylindrical member is rotated to the unlocked position. Contact of pin 64 with the end of cam slot 66 limits the rearward displacement of rear member 34 relative to front member 36.

An arm 68 extends forwardly from the top of rear member 34- through a mating channel 79 in the top of front member 36 so that the front end of the arm may be acted upon, as hereinafter described, to energize bolt assembly 24 for its cyclic functions. A pair of springs 72 are positioned between the rear end of receiver 14 and the rear end of rear member 34 for biasing bolt assembly 24 forwardly to the battery position. A conventional latch 74 is mounted in rear member 34 for vertical displacement and for well-known cooperation with cylindrical member 38 and a pathway 76 in receiver 14 so as to hold the rear member and front member 36 apart in the relative extended position until the front member is in battery position.

A firing pin 78 is mounted in an accommodating bore 80 in cylindrical member 38 for axial displacement therein and is provided with a transverse hole 82 for receiving pin 64 so that the firing pin is displaceable between a retracted and an extended position by the displacement of the rear member relative to front member 36. Mounted in each of the breechblocks 42 is a firing pin 84 which is biased by a coil spring 86 from a striking to a retracted position. A hammer 33 is pivotally mounted in front member 36 rearwardly of each of the firing pins 84 by means of a lateral pin 9%}. Pin 9%) extends through the hammer intermediate the length thereof and is located so that the lower end of the hammer will strike the rear end of the associated one of the firing pins when actuated (FIG. 6). The top end of each hammer 8%; is in contact with a slidable shaft 92 which is longitudinally disposed in front member 36 and is arranged to project from the front end thereof.

Bolt assembly 24 and hammers 88 are energized by a gas system which includes a gas exchange block 94 mounted on barrel l6. Formed on gas exchange block 94 is a gas cylinder )6 which has axial alignment with arm 68 and in which there is slidingly mounted a gas piston $8 having an integral stem 1% the rear end of which extends into receiver 14 for contact with the front end of arm 68. Extending into gas exchange block 94 from the front end thereof and on the right side of gas cylinder 96, looking towards the rear end of firearm 12, is a RH well 1&2 and a Ll-l well 1&4 extends similarly into the gas exchange block on the left-hand side of the gas cylinder. A pair of conduits 1% lead respectively from RH well 102 to a RH gas cylinder ltlfi which is located in receiver 14 in axial alignment with the right one of the shafts $2 and from Ll-I well 194 to a LH gas cylinder 311i) which is located in the receiver in axial alignment with the left one of such shafts. A gas piston 112 is mounted in each LH gas cylinder 110 and RH gas cylinder 16 8 so as to be actuated by the gases discharged thereinto against the associated one of the shafts $2 for driving the associated hammers 38 against the related ones of the firing pins 84-.

A passage 114 provides communication between the center one of the bores 18 and RH well 102. A second passage 116 provides communication between the right one of the bores 18 and LH well 194. A third passage 118 provides communication between the left one of the bores 18 and gas cylinder as.

Magazine 26 is provided with three compartments 1% each of which is adapted for holding a supply of cartridges 22 and successively positioning the cartridges for pickup by head 52 and blocks 42 during displacement of front member 36 to battery position.

Operation Firearm 12 is fired from the open bolt position and, therefore, bolt assembly 24 is releasably held at the rear end of receiver 14 by a conventional sear mechanism (not shown) with front member 36 being held in the extended position relative to rear member 34 by latch '74. Upon release by the sear mechanism, bolt assembly 24 is accelerated forwardly to battery position by springs 72. with three cartridges 22 being picked up by head 52 and breechblocks 4-2 from magazine 26 and transferred into chambers 2%.

When front member 36 reaches battery position with the three cartridges 22 fully seated in the respective chambers 20, latch 74 is actuated to release rear member 34- and permit forward displacement thereof relative to the front member. During this relative forward displacement, pin 64 carried by rear member 34 moves along cam slot 66 to rotate cylindrical member 38 to the locked position and moves firing pin '78 forwardly so that, during the final travel of the rear member, the primer of cartridge 22 in the middle chamber 20 is struck by the fining pin for discharge of the cartridge.

The gases from the discharge of cartridge 22 in the middle bore 18 are bled therefrom through passage 114 to RH well ill and from there by means of the associated conduit 1% to RH gas cylinder 108 for actuation of gas piston 112 therein. The energized gas piston 112 drives against the associated shaft 92 which, in turn,

drives the associated hammer 88 against the related firing pin 84 for discharge of cartridge 22 in the right one of the bores 13. Gases from this discharge are bled through second passage 116 and are used to discharge cartridge 22 in the left one of the bores 18 as hereinbeifore explained. The gases fromthis discharge are bled through third passage 118 to gas cylinder 96 for actuation of gas piston 98 therein against arm 63, whereby rear member 34 is driven rearwardly.

During the initial rearward travel of rear member 34, it moves relative to front member 36, which is locked to receiver 14 by the locking engagement of the lugs 60, so that pin 64 moves along cam slot 66 to rotate head 52 to the unlocked position and retract firing pin '78. When pin 64 reaches the end of cam slot 66, front member 35 is picked up, through the contact therebetween, by rear member 34 for extraction and ejection of the fired cases and is locked to the rear member in the extended position by latch 74. Automatic or semiautomatic fire may be effected by the sear mechanism (not shown).

From the foregoing it is clearly apparent that there is provided herein for salvo-type firearms an operating mechanism which assures that the gas pressure in barrel 16 is reduced to safe limits before bolt assembly 24 is unlocked because bolt assembly 24 remains locked until all of the cartridges 22 have been fired and suitable time is provided during the unlocking of bolt assembly 24 for the gas pressure in the barrel bore 18 to drop to safe limits. It is also evident that recoil impact is reduced by having the cartridges 22 discharged successively in a burst rather than simultaneously.

Although a particular embodiment of the invention has been described in detail herein, it is evident that many variations may be devised within the spirit and scope thereof and the following claims are intended to include such variations.

We claim:

1. In a firearm, the combination including a barrel with a plurality of bores respectively chambered for receiving a cartridge for discharge, a receiver, a cartridge magazine mounted on said receiver, a bolt slidingly mounted in said receiver and adapted for transferring cartridges from said magazine into said bores during displacement to a battery position, means for releasably locking said bolt when in the battery position to said receiver, means for firing said cartridges serially in a salvo, and means for automatically unlocking said bolt from said receiver when the last one of the cartridges in said bores is discharged.

2. The firearm as defined in claim 1 wherein said bolt includes a plurality of breechblocking devices equal to the number of said bores carried by said bolt for displacement therewith, said breechblocking devices being adapted for supporting at discharge the cartridges in said bores, a firing pin slidingly disposed in each of said breechblocking devices, and means for automatically actuating the remaining ones of said firing pins successively for discharge of the associated cartridges after one of said firing pins is actuated to discharge the associated one of the cartridges.

3. The firearm as defined in claim 2 wherein said means for automatically actuating the remaining ones of said firing pins to discharge the associated ones of the cartridges and unlocking said bolt includes a gas system energized by gases produced by the discharges of the cartridges.

4. The firearm as defined in claim 2 wherein said means for unlocking said bolt are energized by the discharge of the last one of the cartridges in said barrel.

5. The firearm as defined in claim 2 wherein said means for unlocking said bolt are energized by gases bled from the one of said bores in which the last one of the cartridges is discharged.

6. The firearm as defined in claim 2 wherein the remaining ones of said firing pins are actuated by an assooiated hammer, and including means in the bolt for striking said hammers successively against the associated ones of said firing pins after said one of said firing pins causes discharge of the related one of the cartridges.

7. The firearm as defined in claim 6 and including in cooperation with each of said hammers a gas cylinder and a piston disposed in said cylinder for actuation against said hammer, means for conducting discharge gases from the previously discharged one of said bores to each of said gas cylinders and means for conducting discharge gases from the one of said bores in which the last one of the cartridges is discharged to a cooperating gas cylinder and piston arranged for energizing said bolt assembly.

8. The firearm as defined in claim 7 wherein one of said breechblocking devices is rotatable into locking engagement with said receiver.

9. The firearms as defined in claim 8 wherein said bolt assembly includes a front member for carrying said breechblocking devices, said breechblocking devices except for said rotatable one thereof being integrally formed in said front member, means for mounting said rotatable breechblocking device in said front member for rotation Without translation, a rear member disposed for longitudinal displacement relative to said front member, and

447,525 3/91 Maxim 89127 XR 1,446,635 2/23 Bcrthlicr 89127 XR BENJAMIN A. BORCHELT, Primary Examiner.

SAMUEL FEINBERG, Examiner. 

1. IN A FIREARM, THE COMBINATION INCLUDING A BARREL WITH A PLURALITY OF BORES RESPECTIVELY CHAMBERED FOR RECEIVING A CARTRIDGE FOR DISCHARGE, A RECEIVER, A CARTRIDGE MAGAZINE MOUNTED ON SAID RECEIVER, A BOLT SLIDINGLY MOUNTED IN SAID RECEIVER AND ADAPTED FOR TRANSFERRING CARTRIDGES FROM SAID MAGAZINE INTO SAID BORES DURING DISPLACEMENT TO A BATTERY POSITION,MEANS FOR RELEASABLY LOCKING SAID BOLT WHEN IN THE BATTERY POSITION TO SAID RECEIVER, MEANS FOR FIRING SAID CARTRIDGES SERIALLY IN A SALVO, AND MEANS FOR AUTOMATICALLY UNLOCKING SAID BOLT FORM SAID RECEIVER WHEN THE LAST ONE OF THE CARTRIDGES IN SAID BORES IS DISCHARGED. 